Our proposed research has two objectives: Our first objetive is to find the correct mechanism for the cooperative ligand binding to proteins. This is to be achieved by extending the sequential model postulated by Koshland et al, and the allosteric transition model postulated by Monod et al. to non-equilibrium kinetic theories to find the time dependent behavior of the cooperative ligand binding to hemoglobin. From our kinetic approch, we intend to resolve the apparent contradictions between the two models and to give more insight into the cooperative mechanism of the ligand binding to proteins. The cooperative ligand binding to mutant hemoglobin will also be investigated. Our second objective is to study the unwinding mechanism of DNA. As a first step toward achieving this difficult project, we intend to study theoretical and experimental aspects of the helix-coil transition of very short oligonucleotides and of moderately long synthetic polynucleotides. We will accomplish our goal theoretically by using the Ising model and experimentally by means of formaldehyde and by use of lasers.